Many contemporary systems include configurations of electrical devices, which are operable to interact by way of information, and data exchange there between, but also need to be provided with electrical power to function. For example, contemporary computer systems often include several modules which are coup able to a computer back plane or mother board by way of electrical connectors; the electrical connectors include power lines for providing electrical power to the modules as well as signal lines for conveying information and data. Such an arrangement is satisfactory in a situation where the modules and the back plane or motherboard remain spatially fixed relative to one another when in operation. However, complications can arise when the modules need to spatially moved relative to the back plane or motherboard when in use. A common contemporary approach to addressing such complications is to employ flexible leads for conveying power to the modules and coupling data signals to and from the modules.
A problem with such flexible leads is that their conductors can work-harden, namely develop fatigue cracks, which can result in fracture and hence in at least partial loss of electrical connection. Another problem is that such flexible leads are often an inconvenience in that they can obstruct desired movement. In contemporary systems requiring appreciable electrical power transfer, flexible leads can become impractically bulky.
In a technical article “Optimized Linear Contactless Power Transmission Systems for Different Applications” by J. M. Barnard et al., 1997 IEEE, linear contactless power transmission systems are described as alternative power supplies to mobile loads. Such systems are elucidated each to comprise an extended primary winding provided with a core slidable in operation along the extended primary winding, the core itself including a secondary winding. The core is fabricated from a material exhibiting a relative magnetic permeability, which is considerably greater than unity for concentrating magnetic flux generated by the primary winding in operation within the core. In operation, alternating electrical power is coupled from the primary winding to the secondary winding. In mining applications in which the contactless power transmission systems are required to transfer up to 15 kW of power there through, the primary winding can have a length approaching substantially 5 meters. These contactless systems are considered in the article only for use in the contactless transfer of power in alternating form from the primary winding to the secondary winding.
When a variable load is coupled to the secondary winding, for example a variable load coupled via switching thyristors or switching power transistor devices for controlling power to the load in a pulse width modulated (PWM) mode of operation, transient surges of power are encountered at the primary winding and can cause potential interference. Such interference can be especially a problem in a situation wherein the load is at least in part digital hardware whose operation is adversely affected by such transient surges; such transient surges can result in data errors and associated consequential malfunction. Moreover, such interference is especially pertinent if a data control signal is communicated via the core concurrently with power being transferred through the core.
A known solution to this problem of interference caused by power transients to data signals is addressed by communicating data via a first medium, for example by optical fiber or wireless, and coupling power via a second medium, for example magnetically as described in the foregoing. However, such solutions can potentially give rise to increased system complexity or potential unreliability in a situation wherein data communication is implemented via wireless, for example WLAN, on account of potential sporadic radio interference. Such an issue of data reliability is especially pertinent in safety-critical applications when controlling powerful apparatus, for example mining equipment, or providing vital functions as in hospital environments.
In view of magnetic coupling being a relatively reliable approach to transfer power and data, it has been appreciated that magnetic couplers can be designed that are operable to at least partially isolate power transfer and data transfer. One approach is to use mutually isolated first and second magnetic couplers for power transfer and data transfer within systems respectively. Such an approach is described in a published U.S. Pat. No. 5,229,652, wherein there is disclosed a non-contact way to provide electrical power and two-way digital communications between a host computer and its peripheral modules; such peripheral modules include, for example, IC memory cards, modems and A/D converters. A magnetic core is employed to provide efficient transfer of both large amounts of electrical power and high-speed digital communications through transformer action. Peripheral modules requiring different power supply voltages or different data voltage levels can be accommodated and intermixed with modules of other types in a same host system. The connector includes detent structures to align the assembly in three dimensions, both upon mating, and under mechanical environmental stress conditions during operation. The magnetic core is provided with both power supply and data windings, the data winding has sections of opposite polarity so that the power supply signal imposed on the data winding cancels itself.
A problem with an approach as described in the aforementioned U.S. Pat. No. 5,229,652 is that inclusion of the detect structures and the implementation of the magnetic core do not allow for relative spatial movement in a manner akin to that described in the aforementioned technical article. Such inability to allow for relative spatial movement whilst providing mutually isolated transformer coupling of electrical power signals and data signals is a technical problem addressed by the present invention.
The present invention is thus directed to at least partially address the aforementioned problem.